The present disclosure relates generally to information handling systems, and more particularly to mismatch detection and correction for physical layer transceiver (PHY) abilities in an auto-negotiation system.
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems such as, for example, networking devices and other computing devices, often include the ability to transmit and receive Ethernet protocol communications via transceivers such as Small Form-factor Pluggable (SFP) transceivers, enhanced Small Form-factor Pluggable (SFP+) transceivers, SPF28 transceivers, 10 Gigabit Small Form-factor Pluggable (XFP) transceivers, Quad(4-channel) Small Form-factor Pluggable (QSFP or QSFP+) transceivers, and/or a variety of other transceivers known in the art. Depending on the type of transceiver used, a port on a computing device may be configured to transmit data in a variety of operation modes according to several variable transmission parameters including, for example, transmission speed, duplex mode, flow control, and/or a variety of other transmission parameters known in the art. Each computing device may have different variable transmission parameters defined by the computing device manufacturer or based on when the computing device was manufactured, and thus any particular computing device may have a different set of operation modes than the computing device(s) to which it is connected.
In order to address the possibility of computing devices transmitting data in different operation modes, auto-negotiation was developed. Auto-negotiation is used by connected computing devices to determine the best operation mode that is shared by each of the connected computing devices. More specifically, auto-negotiation is a physical layer ability used in Ethernet networks to allow two connecting computing devices to negotiate the appropriate variable transmission parameters and settle on the highest, mutually supported set of data transmission operation characteristics. The concept was introduced as part of the Fast Ethernet standard, and has progressed as each new Ethernet technology has come to market, incorporating new technology abilities as required. To keep pace with the rapid evolution of technology in a data center, the networking industry continues to deliver computing devices with higher and higher bandwidth capabilities. For example, the finalization of the Institute of Electrical and Electronics Engineers (IEEE) 802.3bj standard, as well as the introduction of 100 Gbps over 4×25G physical layer (PHY), has opened a path to 25 GbE over a single lane. The 25 Gigabit Ethernet Consortium was formed with the intent to quickly drive a standard for 25 Gigabit Ethernet (GbE) over a single lane based off of the IEEE 802.3bj standard. Shortly after the 25 Gigabit Ethernet Consortium formed, the IEEE 802.3 Task Force for single lane 25 Gbps Ethernet was also formed, and these two bodies continued developing their version of a standard in parallel. As each of these standards leverage the IEEE 802.3bj standard, they are similar, but there were also some slight differences. For example, depending on when a given 25 GbE computing device was introduced to the market, the computing device may have been pre-standard (i.e., both Consortium and IEEE), compliant with the 25 Gigabit Ethernet Consortium standard, compliant with IEEE 802.3by (25 Gigabit Ethernet) standard, or combination with both the 25 Gigabit Ethernet Consortium standard and the IEEE 802.3by (25 Gigabit Ethernet) standard.
With the advent of these standards, auto negotiation as well as other physical layer abilities such as forward error correction (FEC) have become very important for the link to be enabled between computing devices. Because each computing device that is being connected together may have been manufactured at a different point in time with respect to the 25 GbE “standards,” each may have slightly different capabilities and/or default settings. Furthermore, auto-negotiation and FEC settings may vary based on the cable that is plugged into the transceiver. For example, typically auto-negotiation and FEC are enabled at a computing device having a SFP28 transceiver for an SFP28 direct attach copper (DAC) cable, auto-negotiation is disabled and FEC is enabled for an SFP28 active optic cable (AOC) or an SFP28 short range (SR) cable, and both auto-negotiation and FEC are disabled for SFP28 long reach (LR) cables. These different capabilities and/or settings between computing devices (i.e., auto-negotiation mismatch and FEC mismatch) may diminish the functionality of the auto-negotiation capabilities and/or result in a failure to establish a link between the connected computing devices. These issues often require an administrator to manually determine the auto-negotiation and FEC abilities of each machine, determine where the mismatch exists, and manually change the PHY settings in one or both of the computing devices to correct the mismatches.
Accordingly, it would be desirable to provide an improved auto-negotiation system.